Surimyia, a new genus of Microdontinae, with notes on Paragodon Thompson, 1969 (Diptera, Syrphidae) Menno Reemer Reemer, M. Surimyia, a new genus of Microdontinae, with notes on Paragodon Thompson, 1969 (Diptera, Syrphidae). Zool. Med. Leiden 82 (18), 1.i.2008: 177-188, fi gs 1-14, table 1-2.— ISSN 0024-0672. Menno Reemer, National Museum of Natural History, European Invertebrate Survey - The Netherlands, P.O. Box 9517, 2300 RA Leiden, The Netherlands. ([email protected]) Key words: Syrphidae; Microdontinae; Surimyia; Paragodon; new genus; new species; Suriname. Surimyia, a new genus of Microdontinae (Diptera: Syrphidae) is described, based on specimens from Suriname. Surimyia is the only known genus of Syrphidae in which the katatergum (ventral part of lat- eral postnotal sclerite of mesonotum) lacks microtrichia. Within Microdontinae, the genus is unique in the absence of pilosity on the postpronotum. It is also remarkable in the presence of strong, black setae on thorax and abdomen, a character rarely found in Syrphidae. The genus is superfi cially similar in external morphology and colouration to Paragodon Thompson, 1969, but clearly different in the charac- ters mentioned above, as well as in the structure of the male genitalia. Two species are assigned to Surimyia: S. minutula (van Doesburg, 1966) and S. rolanderi spec. nov. Generic morphology is discussed. Differences between the species are described and illustrated. Introduction Hoverfl ies of the subfamily Microdontinae have puzzled taxonomists in many ways. Although traditionally considered as part of the Syrphidae, several authors have advocated family status for this group. Recently it was Thompson (1969, 1972) who proposed to raise the group to family level. This was supported by Speight (1987), but not followed by others. A recent, comprehensive phylogenetic analysis of Syrphidae based on both morphological and molecular characters (Ståhls et al., 2003) placed the Microdontinae as a sister-group of all other Syrphidae. These results do not necessitate family status for the group, nor do they reject it. Another recent analysis, based on an extended set of exclusively morphological characters (Hippa & Ståhls 2005), placed Microdontinae entirely within Syrphidae. Probably, the classifi cation of Microdontinae will remain a matter of debate for some time to follow. Not only adult Microdontinae are challenging, the larvae too have quite a turbu- lent taxonomic history of their own. In the 19th and 20th century, these larvae had been found in ant nests by several biologists, who initially failed to recognize them as Dip- tera-larvae. Their unusual, convex appearance is reminiscent of that of slugs, so much even that they have been described as molluscs on at least four occasions (Haas, 1924, Torres Minguez, 1924, Wheeler, 1908). The connection between these peculiar ‘slugs’ and the adult fl ies of the genus Microdon Meigen, 1803 had already been established by Elditt (1845), but it would take several decades for this knowledge to become com- monly known. At the time of Linnaeus things were simple: he described two Musca-species, which are nowadays placed in Microdon. One of them, Musca mutabilis Linnaeus, 1758, would later be designated as the type species of Microdon by Meigen (1803). At present, ap- 178 Reemer. Surimyia, a new genus of Microdontinae. Zool. Med. Leiden 82 (2008) proximately 400 species of Microdontinae are described, the majority of which are still placed in Microdon. The group is well-represented in all major zoogeographic regions and is most speciose in the tropics, especially the neotropics. Approximately 150 species are known from South America, divided among about 15 supraspecifi c taxa (Thompson et al., 1976). Supraspecifi c taxonomy of Microdontinae has received little attention. Hull (1949) published the only overview so far, and another one is about to be published by Cheng & Thompson (in press). Still, many taxa remain poorly defi ned and relationships are unclear. The present description of a new genus from Suriname is a small contribution to change this situation. For the author, this is the fi rst step in a comprehensive study on the taxonomy and phylogeny of Microdontinae. The genus described here superfi cially resembles Paragodon Thompson, 1969. Upon its description, two species were assigned to Paragodon: P. minutulus (van Doesburg, 1966), based on one male from Suriname, and P. paragoides Thompson, 1969, based on one male from Mexico. Since then no species were added to the genus. The recent col- lection in Suriname of what seemed to be a third Paragodon species prompted a re-ex- amination of the two other species. This revealed that the two species from Suriname, including P. minutulus, actually do not belong to Paragodon, but to a previously unde- scribed genus. This new genus and a new species belonging to it, will be described in this paper. The morphology of the genus is discussed and a comparison with Paragodon is made. A future paper will deal with its phylogenetic relationships, based on both morphological and molecular data. Material and methods The specimens of Surimyia rolanderi spec. nov. were collected in 2006 with malaise traps in the former coffee- and cocoa-plantation Peperpot (district Commewijne, Suri- name), in the southern part, in the La Liberté area (05°46’08,0”N-55°07’33,2”W) (fi g. 1). One malaise trap operated between 2.ii and 27.iv, while a second one operated at the same site (fi ve metres away) between 29.iii and 27.iv. The habitat can be described as moist secondary forest on clay soil. One of the paratypes of S. rolanderi spec. nov. was donated to the collection of the Finnish Museum of Natural History, Helsinki, Finland (MZH), as a DNA voucher spec- imen. Another paratype has been deposited in the United States National Museum (Smithsonian Institution) in Washington D.C., U.S.A. (USNM). The holotype of Cerato- phya minutula Van Doesburg, 1966 has been studied (coll. RMNH, Leiden). A specimen of Paragodon paragoides Thompson, 1969 has been examined from the collection of the Snow Entomological Museum, University of Kansas (SEMC). Male genitalia were macerated in a cold 10% KOH solution for twelve hours, then rinsed in water and subsequently stored in glycerine. The drawings were made with aid of a drawing tube attached to a microscope. The pictures were taken with an Olym- pus motorized stereozoom microscope SZX12 using Analysis Extended Focal Imaging Software. Morphological terminology is based on Thompson (1999), supplemented by some terms used by Hippa & Ståhls (2005). Reemer. Surimyia, a new genus of Microdontinae. Zool. Med. Leiden 82 (2008) 179 Fig. 1. Collection site of Surimyia rolanderi spec. nov.: Peperpot, Suriname, a former coffee- and cocoa- plantation with secondary forest on moist clay soil. Descriptions Surimyia gen. nov. Type species.— Surimyia rolanderi spec. nov. Description.— Very small (4-5 mm) fl ies. Face convex, without facial or frontal tu- bercle. Gena hardly developed, therefore eye bordering the buccal cavity. Antenna with scape at least three times as long as pedicel. Thorax about as long as wide. Postprono- tum bare. Sides of mesonotum, postalar callus and scutellum with strong setae. Ane- pisternum and anepimeron with setae, other pleura bare. Legs without cicatrices, ex- cept in some specimens vaguely expressed at the base of the metafemur. Wing: vena spuria absent, apical crossveins straight, without appendix of vein R4+5 into cell R4+5, crossvein r-m located close to base of discal cell. Abdomen oval, about as long as head and thorax together; lateral margins rolled under ventrally; tergites with setae along posterior margins; sternites with many scattered setae. Male genitalia with bifi d aedea- gus (furcation point around half the aedeagal length), unsclerotized ejaculatory sac and sclerotized, mushroom-shaped ejaculatory apodeme. Diagnosis.— Differs from all other known Syrphidae by the absence of microtrichia on the katatergum (= ventral part of lateral postnotal sclerite, also known as pleuroter- gite). It differs from all other known Microdontinae by the absence of pilosity on the 180 Reemer. Surimyia, a new genus of Microdontinae. Zool. Med. Leiden 82 (2008) postpronotum and otherwise by the presence of strong black setae on thorax, tergites and sternites. Etymology.— The name is a combination of Suriname, where the only known spec- imens of the genus have been found, and myia, the Greek word for fl y. The name is feminine. Surimyia minutula (van Doesburg, 1966) comb. nov. Figs 2-5 Ceratophya minutula van Doesburg, 1966: 89 Paragodon minutulus (van Doesburg, 1966): Thompson (1969) Holotype.— ( (RMNH), Suriname, Zanderij, Malaise trap, 13-16.viii.1964, leg. D.C. Geijskes. Notes on the type specimen.— The holotype is the only known specimen of S. minutula. In this specimen the left wing is missing. Thompson (1969) did not study this type, but included this species in Paragodon based on the drawing by Van Doesburg (1966), which shows many similarities in external morphology and colouration to P. paragoides Thompson. Examination of the holotype revealed that it corresponds to the characters described above as diagnostic for Surimyia (see discussion). The genitalia are fi gured in fi g. 5. There are two minor dissimilarities between the type specimen and the drawing in Van Doesburg (1966). Firstly, the wing is not entirely microtrichose, as the drawing sug- gests, but there are some bare areas basally (fi g. 4). Secondly, the proportions of the anterior and posterior part of vein BM-Cu are not entirely accurate in the drawing: these should be approximately as 1.5 (anterior) : 1 (posterior) (as in fi g. 4). According to Van Doesburg (1966) the face of S. minutula is parallel-sided. Examina- tion of the holotype revealed that the sides of the face are actually slightly converging towards the oral margin (fi g. 2). Surimyia rolanderi spec. nov. Figs 6-13. Holotype.— ( (RMNH), Suriname, Commewijne, Peperpot (plantation), 05°46’08”N-55°07’33”W, ma- laise trap, 17-24.ii.2006, leg.